From d780e6b13e380839b8bfc0d6395a1fb61d76abf2 Mon Sep 17 00:00:00 2001
From: Jack Walker <7463599+Jack-Walker@users.noreply.github.com>
Date: Mon, 30 Mar 2020 19:38:51 -0400
Subject: [PATCH] Updated fixbaserom script

- Script now checks ROM header to determine if ROM is byte swapped.
- Checks the hash of the ROM to determine if it's "vanilla".
---
 fixbaserom.py | 41 +++++++++++++++++++++++------------------
 1 file changed, 23 insertions(+), 18 deletions(-)

diff --git a/fixbaserom.py b/fixbaserom.py
index cc06d78d3a..88c6840249 100644
--- a/fixbaserom.py
+++ b/fixbaserom.py
@@ -2,34 +2,33 @@ import os.path
 from os import path
 import sys
 import struct
+import hashlib
 
 # Read in the original ROM
 if (path.exists("baserom_original.z64")):
     print("File 'baserom_original.z64' found.")
     with open("baserom_original.z64", mode='rb') as file:
-        fileContent = file.read()
-elif (path.exists("baserom_original.n64")):
-    print("File 'baserom_original.n64' found.")
-    print("Byte swapping...")
-    with open("baserom_original.n64", mode='rb') as file:
         fileContent = bytearray(file.read())
-        
-        # Byte Swap ROM
-        # TODO: This is pretty slow at the moment. Look into optimizing it later...
-        i = 0
-        while (i < len(fileContent)):
-            tmp = struct.unpack_from("BBBB", fileContent, i)
-            struct.pack_into("BBBB", fileContent, i + 0, tmp[3], tmp[2], tmp[1], tmp[0])
-            i += 4
 
-            perc = float(i) / float(len(fileContent))
+        # Check if ROM needs to be byte swapped
+        if (fileContent[0] == 0x40):
+             # Byte Swap ROM
+            # TODO: This is pretty slow at the moment. Look into optimizing it later...
+            print("ROM needs to be byte swapped...")
+            i = 0
+            while (i < len(fileContent)):
+                tmp = struct.unpack_from("BBBB", fileContent, i)
+                struct.pack_into("BBBB", fileContent, i + 0, tmp[3], tmp[2], tmp[1], tmp[0])
+                i += 4
 
-            if (i % (1024 * 1024 * 4) == 0):
-                print(str(perc * 100) + "%")
+                perc = float(i) / float(len(fileContent))
+
+                if (i % (1024 * 1024 * 4) == 0):
+                    print(str(perc * 100) + "%")
         
-    print("Byte swapping done.")
+            print("Byte swapping done.")
 else:
-    print("Error: Could not find a baserom_original.z64 or baserom_original.n64.")
+    print("Error: Could not find baserom_original.z64.")
     sys.exit(1)
 
 # Strip the overdump
@@ -40,6 +39,12 @@ strippedContent = list(fileContent[0:0x3600000])
 print("Patching header...")
 strippedContent[0x3E] = 0x50
 
+# Check to see if the ROM is a "vanilla" Debug ROM
+md5Hash = hashlib.md5(bytearray(strippedContent)).hexdigest()
+
+if (str(md5Hash) != "f0b7f35375f9cc8ca1b2d59d78e35405"):
+    print("Error: Expected a hash of f0b7f35375f9cc8ca1b2d59d78e35405 but got " + str(md5Hash) + ". The baserom is probably not \"vanilla\"")
+    sys.exit(1)
 
 # Write out our new ROM
 print("Writing new ROM 'baserom.z64'.")